Well, Bought the used SuperSplit today!

Went to check it out and ran a few of my toughest pieces through it. Crotch of black walnut that I couldn't crack by hand, took three shots but did go through it. I'm impressed. Picked her up for $975. Has a ~3 yeard old B&S Intek 5.5HP engine on it. Seems to have been maintained well. This is an older model where the rail is only 18" off the ground so its not so hard to get the larger pieces on it. I'll need to fabricate a table for it so I'm not consistently picking up both halves of the splits to re-split. I've got pics posted here.

Now I just need to put it through its paces with my large pile of maple waiting in the driveway...

I think you may be able to raise it up if you like, which will help save your back (it does for me anyway). On mine, the axle is connected to the frame of the unit by 1 1/2 or 2" threaded pipe, so it should be pretty easy to raise it up to whatever height you like.